Sunderland boss Martin O'Neill has confirmed winger James McClean has been the target of death threats.
The 23-year-old Republic of Ireland international came in for criticism after opting not to sport a Remembrance Day poppy on his shirt during the Black Cats' 2-1 defeat at Everton last weekend.
McClean was introduced by O'Neill as a second-half substitute in today's 3-1 win at Fulham and received a mixed response from the travelling Sunderland supporters.
Following the victory O'Neill backed McClean to cope with a few jeers and revealed the Republic of Ireland international has also received death threats.
"James will deal with it (the booing). I think it is to do with the issue last week, it's a free choice in this world," he said.
"James has lived with a lot of things - he's getting death threats too now so that doesn't help."
Police have since opened an investigation into the death threat allegations.
A statement released by Northumbria Police read: "Police are carrying out inquiries following a third party report of threats made on social networking sites.
"Officers have spoken to Sunderland AFC and inquiries are ongoing."